In connection with modern control or regulation of internal combustion engines, especially for automotive vehicles, to achieve optimal running of the engine is accomplished by preselecting the control or regulation by selecting respective cylinder, i.e., to achieve the driving of a certain cylinder in coordination with the others, but which can be correctible on an individual basis. Increased complexity in the area of the circuitry is the price of obviously achieved advantages. Such circuitry is known from EP-OS No. 152 287.
If, for instance, a cylinder-selective fuel injection engine is considered, it becomes necessary to have the ability to actually drive each single injection valve. For this purpose, timer-controlled outputs at the micro-controller of the circuitry have traditionally been required. Such outputs are connected via hardware with the timer in order that the condition of these outpus can be influenced directly, without an interrupt program. However, if other functions, such as ignition and control of knocking, are to be controlled or regulated by means of this microcontroller, such outputs are also necessary for this. In presently available microcontrollers, however, such outputs are not available in sufficient numbers and even when considering future developments, the need for such output will in any case lead to an increase in costs.
Another problem in connection with comparable traditional circuitry lies in the fact that they are not, at the same time, usable for engines with a different number of cylinders, requiring adaptation of the basic software to the number of cylinders and, if necessary, to the ignition sequence. In contrast thereto, it is desirable for reasons of cost to be able to use the same circuitry and software for different internal combustion engines and, at most, to provide individualization via specific modules.